What are the guidelines for supplementary files (figures, Multimedia Appendix, additional material for reviewers/editors only)?

You can/should leave figures in the manuscript file during the initial round(s) of peer-review, but also upload high-quality figures as image (PNG/JPG) files as supplementary files. Do not upload a .docx, PDF, .gif, .pptx, etc. file to be used as a figure.

Figures should not have any transparent sections; our system will render them incorrectly. Extremely large images (ie, 5000+ pixels in either direction) will also render incorrectly.

For manuscripts discussing web-based or mobile interventions we usually require 1-2 screenshots of the intervention as figure. Also, upload an "illustrative" figure or photo to be used for our homepage and the table-of-contents (we call this a "TOC image", see below), but make sure this is uploaded into the correct category (not Figures, see below).

Each figure must have a caption which can be entered into the "Description" box. Use sentence case for the caption (as opposed to title case).

By the way: Please do not use pie diagrams, ever. Our readers are sophisticated enough to know how "10%" looks like and do not need pie diagrams to help them visualize it. These kind of data (relative and absolute data) should be reported in the text or tables.

Important: After acceptance, the final paper is generated from the uploaded image files (rather than from what is in the Word manuscript file) and from what you enter in the field "caption/description" when you upload a figure or appendix. After acceptance, all figures will be removed from the manuscript and we will only use the images/captions uploaded to the system.

Multimedia Appendix

Multimedia Appendices (MAs) are published at the end of a paper.

MAs can be questionnaires, datasets, videos/screencasts, Powerpoint or PDF files showing multiple screenshots (please also use 1-2 screenshots as figures in the paper), files containing the source code of a computer program, informed consent documents.

We recommend to upload a tracked-changes version, and also the responses to the reviewers, as additional file. Also, upload potentially overlapping material/publications submitted or published in other journals (make sure to outline in your notification to the editor how this paper is different, and why "salami-slicing" into multiple publications is justifiable).